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Biomedical subjects

Y Serizawa

Publications and source records attributed to Y Serizawa.

12 recordsLinked to original sources
PubMed2001

Intravesicular Fas localization in epithelial cells of castrated rat prostate glands.

Androgenic steroids regulate the development and size of mammalian prostate epithelial cells. To evaluate the relationship between Fas-Fas ligand system and apoptosis in prostate epithelial cells of the castrated rats, we have examined immunocytochemical localization of Fas antigen in the castrated rat prostate glands at a series of different times. We used a rabbit polyclonal anti-Fas antibody with a streptavidin-biotin method and confocal laser scanning method or an immunogold method. Fas immunolocalization was examined in ventral lobes of prostate glands taken from intact or castrated adult male Wistar rats on day 1, 2, 3, 4 and 5 by light or electron microscopy. At a light microscopic level, the castrated prostate epithelial cells showed mostly Fas immunolocalization in their apical parts of cytoplasm on day 2 after the castration. In addition, their extent of the Fas expression was expanded throughout the cytoplasm in proportion to the androgen ablation periods, and later the Fas expression was detected at luminar or basolateral sides of the epithelial cells. Both immunogold labeling with ultrathin sections and immunoperoxidase technique with cryostat sections demonstrated that Fas was localized mainly in secretory granules of the castrated prostate epithelial cells and some parts of their cell membranes at later stages. Our immunocytochemical findings showed that Fas expression was time-dependently induced in most of the prostatic epithelial cells after castration of rats. The rate of Fas-expressing epithelial cells was too high and inconsistent with the previously reported rate of TUNEL-positive ones. The membrane-associated Fas may have little effect on the apoptosis in the present case, bacause a lot of soluble Fas was secreted from the prostatic epithelial cells. A further study is needed to clarify some significance of the secretory Fas in the prostatic epithelium after the rat castration.

Animals↗
PubMed1998

Microparticle resins as a potential nasal drug delivery system for insulin.

The application of various resins for the nasal delivery of insulin was examined in rabbits. Intranasal administration of human insulin (28 U, 1 mg) mixed with fractionated sodium polystyrene sulfonate powder (an anionic resin with a particle size of 20-45 microns) caused a rapid increase of the plasma insulin level 413.0 +/- 71.7 microU/ml (mean +/- S.D.) after 15 min, while intranasal administration of insulin alone caused little increase. The blood glucose level decreased from 118.8 +/- 18.5 mg/dl to 65.8 +/- 13.8 mg/dl at 45 min after administration. These results were superior to those obtained with the unfractionated resin. Styrene-divinylbenzene copolymer (a nonionic resin; 20-45 microns fraction) showed similar enhancement of nasal insulin absorption. In contrast, polyacrylester (a nonionic resin; 20-45 microns fraction) and cholestyramine (a cationic resin) did not promote insulin absorption. These results suggest that some resins may be useful for nasal delivery of insulin.

Administration, Intranasal↗
PubMed1995

Spontaneous resolution of an acute spontaneous spinal epidural hematoma without neurological deficits.

A 46-year-old woman presented with sudden severe pain in the interscapular region. Physical examination, including detailed neurological evaluation, did not disclose any abnormalities. However, magnetic resonance imaging revealed an epidural hematoma anterior to the thoracic spinal cord and its spontaneous resolution thirty days after onset. Her hospital course was uneventful. To our knowledge, this report documents the first case of a spontaneous spinal spidural hematoma without neurological deficits. Spinal epidural hematoma may be more common than previously thought because some cases have probably been misdiagnosed as transient back pain of unknown etiology.

Acute Disease↗
PubMed1980

Adrenal chromaffin cells in the stressed mouse.

Mice were supinely restrained on a board by pinning the limbs. The board was then made to stand vertically and immersed in water to the height of the hind limbs of the animals. At 4 ao 28 hr after this restraint plus water-immersion stress, a remarkable decrease in the number of secretory granules in the chromaffin cells was light microscopically demonstrated in silver-impregnated and toluidine-blue-stained semithin sections. Exocytotic invaginations containing pleomorphic granule materials were demonastrated by thin section and freeze-fracture replica electron microscopy. This stress-induced exocytotic degranulation of the chromaffin cells was accompanied by the occurrence of numerous small cytoplasmic vesicles resembling the synaptic-type vesicles of the small granule chromaffin cells.

Adrenal Medulla↗
PubMed1979

Stress-induced degranulation accompanied by vesicle formation in the adrenal chromaffin cells of the mouse.

Stress was induced in mice by restraining on a board by pinning their limbs followed by immersion of the hind feet in a water bath of 20 degrees C. Fine structure of adrenal chromaffin cells was studied by light and electron microscopy. After 8 to 22 hrs' stress, remarkable decrease in the number of argentaffin granules of the NA cells was demonstrated by light microscopy. By electron microscopy, the decline in the granule number was marked in A, NA and SGC cells. This degranulation was accompanied by theoccurrence of numerous smally cytoplasmic vesicles which often appeared empty but sometimes contained an electron-dense material. Granule-containing invaginations of plasma membrane were frequently seen and were interpreted to represent the exocytotis profiles. The idea that the secretory granule membrane and associated substances might be recovered in the form of cytoplasmic vesicles was thus supported. Exposure of the mouse to restraint plus water immersion stress proved to be a simple method for production of acute and drastic degranulation of the adrenal chromaffin cells.

Adrenal Glands↗
PubMed1979

Neuro-insular complex type I in the mouse. Re-evaluation of the pancreatic islet as a modified ganglion.

Autonomic ganglia in the pancreas may include islet cells; while islets sometimes contain a group of ganglion cells. Electron microscope observation in adult mice confirms occurrence of a structure called neuro-insular complex type I by Fujita (1959), in which islet cells are juxtaposed to nerve cells either directly or by intercalation of a thin glial cell cytoplasm. Islet cells are equivalent to neurons in their attitude towards neurons and towards glial elements in the neuro-insular complex. There seems to be every gradation between pure ganglia, mixed forms representing the neuro-insular complexes, and pure islets. Pancreatic islets may thus be regarded as modified ganglia.

Animals↗
PubMed1978

SGC (small granule chromaffin) cells in the mouse adrenal medulla: light and electron microscopic identification using semi-thin and ultra-thin sections.

Adrenal glands of the mouse, fixed either in glutaraldehyde followed by osmium tetroxide or in a mixture of potassium dichromate and glutaraldehyde, and embedded in Epon 812, were investigated by light and electron microscopy. An argentaffin reaction was applied to semi-thin sections for light microscopy and to ultra-thin sections for electron microscopy. Since the mature secretory granules in the Small Granule Chromaffin (SGC) cell were argentaffin and were mainly located along the cell membrane, this cell was clearly distinguishable under the light microscope both from the A (adrenaline) cell whose secretory granules were non-argentaffin and from the NA (noradrenaline) cell whose cytoplasm was rich and was filled with large, strongly argentaffin granules. Chromaffinity of the SGC cell was demonstrated under the light microscope. The SGC cell was intensively stained with toluidine blue without revealing metachromasia. It was demonstrated at the EM level that not only the secretory granules but also the synaptic-like vesicles in the SGC cell contained argentaffin substances. Possible functional relationship between the secretory granules and the synaptic-like vesicles was discussed.

Adrenal Medulla↗